Upon first glance, BBC One and Netflix’s River feels a bit like a Mad Libs version of a prestige drama. Part character study and part crime story (with a dash of the supernatural), the series makes use of tropes and character archetypes that are well-tread territory in the hour-long landscape. A Difficult Genius hell-bent on avenging the death of a loved one? Check. A sardonic, eager-to-please (and diverse to boot) sidekick? Check. Add in a wise, compassionate boss able to see past our genius’ eccentricities, and you’ve got all the makings of a successful police procedural – as well as most cable heavyweights.

Despite River’s willingness to exploit the wheel rather than reinvent it, the series does manage to distinguish itself as more than just a carbon copy of shows we’ve already seen.

For starters, River is more interested in the emotional journey of its characters than simple police work. Using the framework of a season-arching mystery, the show quickly becomes a fascinating exploration of human grief. The result is an intelligent, unsettling, impeccably acted drama that does not shy away from dealing with social issues like mental illness, immigration, and the racial and class biases inherent in the justice system.

Unfortunately, being more than your average police procedural doesn’t quite save River from trying to do too many things at once – and only some of them well.

From the brain of creator Abi Morgan (The Hour, The Iron Lady), River centers on Detective John River (Stellan Skarsgård) a brilliant, broken cop who is still deep in the throes of grief three weeks after witnessing the murder of his former partner, Jackie “Stevie” Stevenson (Nicola Walker). Restless and haunted, River attempts to balance his personal quest to solve Stevie’s case with the cases actually assigned to him. All the while, River must adjust to a new partner, DS Ira King (Adeel Akhtar), fend off the worries of his boss and friend DCI Chrissie Read (Lesley Manville), and learn to trust police psychologist Rosa (Georgina Rich), with whom he is forced to attend counseling sessions. As River dives into Stevie’s past, he struggles to reconcile the memory of his beloved partner with the secret life she was leading right under his nose.

While River tries to manage the external pressures in his life, it is his internal struggle that consumes him. River is not simply a dedicated cop who can’t get work off the brain. Instead, he is quite literally surrounded by those whose deaths he has yet to make sense of. Whether it be Stevie, a victim in one of his cases, or even the 19th century serial killer Dr. Thomas Cream (Eddie Marsan), these visions are not of the supernatural variety. They are, instead, what River recognizes as “manifests” – figments of his imagination, and evidence of his debilitating mental illness. These manifests appear as clear and human to us on screen as they do to River, and they act as if they are still living – sharing memories, probing, and (at their worst) antagonizing him.

The flashy hook of a cop who can see dead people may seem hokey or derivative at first, but the series’ fantastical moments are grounded by tremendous performances from all of its lead players, particularly Skarsgård. As River, Skarsgård is compelling and devastating, artfully embodying the complexities and contradictions inherent in mental illness and trauma. He effortlessly jumps from anguished loner to kind confidant to rage-filled avenger several times throughout a given episode. The actor truly carries the show, making a character that could easily come across as disjointed resonate both as defeated patient and talented detective.

Skarsgård is at his best in his scenes with Walker. While his River is dark grey, her Stevie is all bright lights and disco music. She’s funny, playful, blunt, and unafraid to call River out for being the grump that he is. The warmth between the two characters is palpable and magnetic, whether they are arguing over milkshakes or reminiscing about the time Stevie nursed River back to health after an injury. It’s easy to see how the world feels emptier without her – for almost every character in the show. Walker is incredible in the role, pulling off an understated confidence as Stevie begins to drift from the partner River remember and her double-life comes to light.